There is a conventionally well-known technology that provides an in-wheel motor inside wheels of an electric vehicle and that drives the wheels with the in-wheel motor. With such an electric vehicle, there is no need to install an engine or a motor in the vehicle body, and is advantageous in the point of being able to increase the internal space of the vehicle body, such as its room space and luggage space. The vehicle body of the electric vehicle is connected with an in-wheel motor via a suspension device. The vehicle body is also installed with a controller unit of the in-wheel motor, a battery, and an inverter. The in-wheel motor connected to a lower part of the spring in the suspension device (wheel side) is then connected to an inverter installed at an upper part of the spring in the suspension device (vehicle body side) with a power line. Conventionally, for example, power lines such as those described in Japanese Patent No. 4511976 (Patent Document 1) and Japanese Patent No. 4628136 (Patent Document 2) are known as power lines that supply electric power from the inverter to the in-wheel motor.
Due to the function of the suspension device, the in-wheel motor changes its position with respect to the vehicle body in vertical directions, or steers in the left-right directions. Therefore, it is necessary to appropriately support the middle parts of the power line so that no unnatural bending occurs to the power line. In the power line wiring arrangement described in the Patent Document, the middle part of the power line is attached to an end plane of the in-wheel motor by a clamp member. Moreover, the surface of the in-wheel motor described in the Patent Document has a plurality of fins vertically arranged thereon. Moreover, in the power line wiring arrangement described in the Patent Document, a terminal box is provided on an outer peripheral surface of a tubular wall among a tubular-shaped in-wheel motor, and ends of three power lines are connected to this terminal box.